Compendium of Cancer Genome Aberrations

HAEM5:Primary cutaneous marginal zone lymphoma: Difference between revisions

[unchecked revision][unchecked revision]
← Older editNewer edit →
VisualWikitext
No edit summary
Line 34: Line 34:
|Primary cutaneous marginal zone lymphoma
|Primary cutaneous marginal zone lymphoma
|}
|}
==Definition / Description of Disease==
Primary cutaneous marginal zone lymphoma (PCMZL) is an indolent non-Hodgkin lymphoma arising in skin without evidence of extracutaneous disease at the time of diagnosis. The tumor is comprised of monotypic, CD5-negative, CD10-positive neoplastic small B-cells with monotypic plasma cells, and a variable number of reactive T-cells infiltrating the dermis, often forming follicles with reactive germinal centers. Clonal immunoglobulin rearrangement may be present, thus determining the subtype as class-switched versus non-class-switched heavy-chain immunophenotype. There must be no evidence of extracutaneous disease at the time of diagnosis and other cutaneous lymphomas must be excluded. 
Put your text here <span style="color:#0070C0">(''Instructions: Brief description of approximately one paragraph - include disease context relative to other WHO classification categories, diagnostic criteria if applicable, and differential diagnosis if applicable. Other classifications can be referenced for comparison.'') </span>
==Synonyms / Terminology==
*Primary cutaneous marginal zone lymphoproliferative disorder (acceptable)
*Primary cutaneous immunocytoma (historical; no longer in use)
*Primary cutaneous plasmacytoma (historical; no longer in use)
==Epidemiology / Prevalence==
*30-40% of all primary cutaneous B-cell lymphomas
*Predominantly affects adults in the fifth and sixth decades of life
*Male preponderance
*Unknown etiology in most cases
*Possible causes include chronic antigenic stimulation by intradermally applied antigens (e.g. tattoo pigments, vaccines, tick-borne bacteria, etc.)
*Association with ''Borrelia burgdorferi'' infection in endemic Europe but not associated in USA or Asia
*Patients tend to have increased gastrointestinal disorders and various autoimmune diseases as well
==Clinical Features==
*
*Present with multifocal or, less frequently, solitary red or violaceous plaques or nodules
==Sites of Involvement==
*Skin
**Most commonly on the trunk and arms
==Morphologic Features==
*Dense dermal infiltrate composed of:
**Small lymphocytes
**Plasma cells
***Located at periphery of lymphoid infiltrates or in subepidermal compartment
***Heavy chain immunophenotype show different morphologies:
****Non-class-switched forms
*****Sheets of B-lymphocytes and few T-lymphocytes
*****Scattered plasma cells
****Class-switched forms
*****Large number of reactive T-lymphocytes but can occasionally be obscured by the neoplastic B cells
*****Peripherally clustered monotypic plasma cells
**Follicles with reactive germinal centers (most cases)
**clusters of plasmacytoid dendritic cells at periphery of infiltrates
==Immunophenotype==
*Neoplastic B cells have the following immunophenotype:
{| class="wikitable sortable"
|-
!Finding!!Marker
|-
|Positive
|CD20
|-
|Positive
|CD22
|-
|Positive
|CD79a
|-
|Positive||BCL2
|-
|Negative||CD5
|-
|Negative||CD10
|-
|Negative||BCL6
|-
|Negative
|Cyclin D1
|}
*Associated reactive germinal centers B cells
**BCL6 positive
**BCL2 negative
*Plasmacytoid dendritic cells
**CD123 positive
*Plasma cells
**CD138 and CD79a positive
**Plasma cells often have monotypic expression of immunoglobulin light chains
**The immunoglobulin heavy chain can be either non-class-switched or class-switched
***Non-class-switched heavy chain
****Produce IgM
****Positive for CXCR3 expression
****Approximately 10% of cases have IgM positivity
***Class-switched heavy chain
****Produce IgG, IgA, or IgE
****No expression of CXCR3
****Approximately 90% of cases have IgG, IgA, or IgE positivity
**IgG4 expressed by plasma cells in 13-35% of cases, though not related to IgG4-related disease.


==WHO Essential and Desirable Genetic Diagnostic Criteria==
==WHO Essential and Desirable Genetic Diagnostic Criteria==
Line 420: Line 324:
==Additional Information==
==Additional Information==


*Favorable prognosis
*Favorable prognosis (5-year disease-specific survival rate >98%)
**5-year disease-specific survival rate >98%
*Recurrence is common
*Recurrence is common
*4% of patients will have extracutaneous spread, particularly in patients with longstanding multifocal disease
*4% of patients will have extracutaneous spread, particularly in patients with longstanding multifocal disease
This disease is <u>defined/characterized</u> as detailed below:
* Primary cutaneous marginal zone lymphoma (PCMZL) is an indolent non-Hodgkin lymphoma arising in skin without evidence of extracutaneous disease at the time of diagnosis. The tumor is comprised of monotypic, CD5-negative, CD10-positive neoplastic small B-cells with monotypic plasma cells, and a variable number of reactive T-cells infiltrating the dermis, often forming follicles with reactive germinal centers. Clonal immunoglobulin rearrangement may be present, thus determining the subtype as class-switched versus non-class-switched heavy-chain immunophenotype. There must be no evidence of extracutaneous disease at the time of diagnosis and other cutaneous lymphomas must be excluded.
The <u>epidemiology/prevalence</u> of this disease is detailed below:
*30-40% of all primary cutaneous B-cell lymphomas
*Predominantly affects adults in the fifth and sixth decades of life
*Male preponderance
*Unknown etiology in most cases
*Possible causes include chronic antigenic stimulation by intradermally applied antigens (e.g. tattoo pigments, vaccines, tick-borne bacteria, etc.)
*Association with ''Borrelia burgdorferi'' infection in endemic Europe but not associated in USA or Asia
*Patients tend to have increased gastrointestinal disorders and various autoimmune diseases as well
The <u>clinical features</u> of this disease are detailed below:
Signs and symptoms - Present with multifocal or, less frequently, solitary red or violaceous plaques or nodules
Laboratory findings - N/A
The <u>sites of involvement</u> of this disease are detailed below:
* Skin (most commonly on the trunk and arms)
The <u>morphologic features</u> of this disease are detailed below:
Dense dermal infiltrate composed of:
*Small lymphocytes
*Plasma cells
**Located at periphery of lymphoid infiltrates or in subepidermal compartment
**Heavy chain immunophenotype show different morphologies:
***Non-class-switched forms
****Sheets of B-lymphocytes and few T-lymphocytes
****Scattered plasma cells
***Class-switched forms
****Large number of reactive T-lymphocytes but can occasionally be obscured by the neoplastic B cells
****Peripherally clustered monotypic plasma cells
*Follicles with reactive germinal centers (most cases)
*Clusters of plasmacytoid dendritic cells at periphery of infiltrates
The <u>immunophenotype</u> of this disease is detailed below:
* Positive (neoplastic B cells) - CD20, CD22, CD79a, BCL2
* Negative (neoplastic B cells) - CD5, CD10, BCL6, Cyclin D1
*Positive (associated reactive germinal centers B cells) - BCL6
*Negative (associated reactive germinal centers B cells) - BCL2
*Positive (plasmacytoid dendritic cells) - CD123
*Positive (plasma cells) - CD138, CD79a
**Plasma cells often have monotypic expression of immunoglobulin light chains
**The immunoglobulin heavy chain can be either non-class-switched or class-switched
***Non-class-switched heavy chain
****Produce IgM
****Positive for CXCR3 expression
****Approximately 10% of cases have IgM positivity
***Class-switched heavy chain
****Produce IgG, IgA, or IgE
****No expression of CXCR3
****Approximately 90% of cases have IgG, IgA, or IgE positivity
**IgG4 expressed by plasma cells in 13-35% of cases, though not related to IgG4-related disease.


==Links==
==Links==
Retrieved from "https://test.ccga.io/index.php/HAEM5:Primary_cutaneous_marginal_zone_lymphoma"